http://www.mathmontada.net/vb/upload...1367180386.jpg

Printable View

- April 28th 2013, 12:20 PMabualabedSUM
- April 28th 2013, 12:50 PMBradynsRe: SUM
Does this help?

sum n(21-n) from n=1 through 20 - Wolfram|Alpha - April 28th 2013, 12:50 PMPlatoRe: SUM